1. Field of Invention
The present invention relates to a semiconductor device.
2. Description of Related Art
In recent years, semiconductor devices in which a flexible circuit substrate and a semiconductor chip are coupled to one another and sealed by resin are used. A method of lowering the power source impedance of such a semiconductor device and reducing electrical noise is described, for example, in Japanese Laid-open Patent Application HEI 5-82585 at column 9 and FIG. 2 thereof. The conventional structure of the semiconductor device will be described below with reference to FIG. 9.
A semiconductor chip 1 has a plurality of signal pads (signal electrodes) 4, power source pads (power source electrodes) 7 and grounding pads (grounding electrodes) 9 provided on an active surface of the chip 1. These pads are treated with a bump forming process. A TAB tape 2 defines a device hole 5, and has a plurality of signal leads 3 protruding into the device hole 5, and a power source common lead 6 and a grounding common lead 8 extending across the device hole 5. The signal leads 3 are electrically, directly connected to predetermined ones of the signal pads 4 Further, the power source common lead 6 is electrically, directly connected to all of the plurality of power source pads 7, and the grounding common lead 8 is also electrically, directly connected to all of the plurality of grounding pads 9. The leads 3, 6 and 8 and the pads 4, 7 and 9 are electrically connected by a package connecting method using heat and pressure.
However, in the above-described conventional semiconductor device, each of the power source common lead and the grounding common lead is narrower than the width of each of the bumps formed for the power source pads and the grounding pads, and therefore the power source impedance cannot be sufficiently reduced. Furthermore, when these common leads are electrically connected to the corresponding pads by heat-and-pressure bonding, stress is generated by the heat and the pressure applied to the common leads. As a result, cracks are likely generated in the common leads, and the cracks may develop after the device is assembled in an electronic device and may eventually result in the snapping of the common leads.
Also, when an electronic device is provided with the conventional semiconductor device, the power source impedance cannot be sufficiently lowered. As a result, the electronic device with high-frequency operation or with high current consumption is suffered from problems in which electrical noise cannot be improved. Moreover, since line-breaking problems are likely to occur in the power source line and the grounding line, it is difficult to secure long-term reliability.
Also, in the above-described semiconductor device, the power source common lead 6 and the grounding common lead 8, that protrude into the device hole 5 of the TAB tape 2, are supported only by their own ends, respectively. As a result, the leads 6 and 8 slacken by their own weight, and therefore, positioning of the leads with respect to the power source pads 7 and the grounding pads 9 is difficult.
It is an object of the present invention to provide a semiconductor device which has a sufficiently low power source impedance, and eliminates line-snapping problems that may occur in a power source common lead and a grounding common lead.
Furthermore, it is another object of the present invention to facilitate positioning of a power source common lead or a grounding common lead with respect to power source electrodes or grounding electrodes, respectively.
It is also another object of the present invention to provide an electronic device that reduces electrical noise and assures a long-term reliability.
To achieve the above-described objects, a semiconductor device of a first aspect of the present invention is formed, for example, from a semiconductor chip, a circuit substrate including a flexible insulation substrate and conductor patterns formed thereon, and sealing resin. The conductor patterns that protrude into an opening defined in the flexible insulation substrate are coupled to the semiconductor chip, and the coupling section is sealed by the sealing resin. It is preferred that at least one of the conductor patterns is formed to extend across the opening and has a specified width wider than a pad for connecting to the semiconductor chip.
In accordance with the invention thus structured, the conductor pattern that defines a common lead extending across the opening has a width wider than the pad for connecting to the semiconductor chip. As a consequence, the current carrying capacity is increased and the power source impedance is substantially lowered.
In a semiconductor device of a second aspect of the present invention, the conductor pattern formed to extend to across the opening preferably has a bent section at least one location.
In accordance with this embodiment, the bent section reduces the stress generated in the conductor pattern when it is electrically connected to the corresponding pads so that generation of cracks in the conductor pattern can be prevented. Consequently, it is effective in preventing the line-snapping resulting from cracks which may grow after assembled in an electronic device.
An electronic device of a third aspect of the present invention includes a semiconductor device as described above, and one of a display device, a printing device and a computer device which is driven by the semiconductor device
In accordance with the above-described invention, the power source impedance is substantially lowered and the electrical noise is improved because of the provision of a semiconductor device set forth in the first aspect. Also, the line-snapping of the power source line is eliminated and a substantially long-term reliability is secured because of the provision of a semiconductor device set forth in the second aspect.
A semiconductor device of a fourth aspect of the present invention is preferably formed from a semiconductor chip, a circuit substrate including a flexible insulation substrate and conductor patterns formed thereon, and sealing resin. The conductor patterns that protrude into an opening defined in the flexible insulation substrate are coupled to the semiconductor chip, and the coupling section is sealed by the sealing resin. It is preferred that at least one of the conductor patterns is formed to extend across the opening and has at least one or more connection branch, wherein the connection branch has a specified width narrower than a pad for connecting to the semiconductor chip.
In accordance with the above-described invention, the connection branch branching out the conductor pattern and having a width narrower than the pad is used to electrically connect the pad to the conductor pattern. As a result, the width of the conductor pattern can be made wider without making the post-connection examination difficult, and therefore the power source impedance can be substantially lowered.
In a semiconductor device of a fifth aspect of the present invention, the conductor pattern formed to extend across the opening in the semiconductor device described above preferably has a specified width wider than the pad. As a result, the current carrying capacity of the conductor pattern is made larger and the power source impedance is substantially lowered.
In a semiconductor device of a sixth aspect of the prevent invention, the conductor pattern formed to extend across the opening in the semiconductor device set forth above preferably has a bent section at least one location thereof. This results in the same effect obtained by the invention set forth in the second aspect.
An electronic device of a seventh aspect of the present invention preferably includes a semiconductor device described above, and one of a display device, a printing device and a computer device which is driven based on the semiconductor device. In accordance with this invention, the power source impedance is substantially lowered and the electrical noise is improved without making the post-connection examination difficult as a result of the provision of a semiconductor device set forth in the fourth aspect. Also, the line-snapping of the power source line is eliminated and a substantially long-term reliability is secured because of the provision of a semiconductor device set forth in the fifth aspect.
A semiconductor device of an eight aspect of the present invention is preferably formed from a semiconductor chip, a circuit substrate including a flexible insulation substrate and conductor patterns formed thereon, and sealing resin. The conductor patterns that protrude into an opening defined in the flexible insulation substrate are coupled to the semiconductor chip, and the coupling section is sealed by the sealing resin. It is preferred that at least one of a power source electrode and a grounding electrode of the semiconductor chip is larger than a signal electrode thereof.
In the invention thus structured, the power source electrode or the grounding electrode of the semiconductor chip, in which a larger current flows than in the signal electrode, is preferably made larger than the signal electrode. As a result, the power source impedance is lowered and the electrical noise is improved. Also, the number of power source electrodes or grounding electrodes of a semiconductor chip can be reduced, with the result that further miniaturization and simplification of a semiconductor device are achieved.
In the semiconductor device of a ninth aspect of the present invention, the conductor patterns that define common leads to be connected to the power source electrode or the grounding electrode are also preferably formed to extend across the opening of the flexible insulation substrate. The conductor patterns are formed to have a width wider than the power source electrode or the grounding electrode, and provided with connection branches having a width narrower than the electrode. Also, the connection branch may be connected to the flexible insulation substrate.
An electronic device of a tenth aspect of the present invention preferably includes a semiconductor device set forth above, and one of a display device, a printing device and a computer device which is driven based on the semiconductor device. The electronic device of the present invention thus structured provides the same effects described above.
A semiconductor device of an eleventh aspect of the present invention is preferably formed from a semiconductor chip, a circuit substrate including a flexible insulation substrate and conductor patterns formed thereon, and sealing resin. The conductor patterns protrude into an opening defined in the flexible insulation substrate, and are coupled to the semiconductor chip. The coupling section is sealed by the sealing resin. It is preferred that at least one of the conductor patterns is formed to extend across the opening, and has at least one or more branch, wherein the branch has a tip section connected to the flexible insulation substrate.
In accordance with the invention thus structured, since the tip sections of the branches are connected to the flexible insulation substrate, the branches act as support members to support the conductor patterns that define common leads and extend across the opening. Therefore, the common leads and the electrodes of the semiconductor chip are readily and securely aligned with one another.
In a semiconductor device of a twelfth aspect of the present invention, the branches preferably define connection branches to be coupled to the semiconductor chip. In accordance with the invention thus structured, the common leads and the electrodes of the semiconductor chip are readily and correctly aligned with one another. Moreover, the width of the conductor pattern can be made wider without making the post-connection examination difficult, and thus the power source impedance is substantially lowered. Moreover, the conductor patterns extending across the opening may be provided with bent sections in a similar manner as the above-described invention, and the connection branch may preferably be formed to have a width narrower than the pad.
An electronic device of a thirteenth aspect of the present invention preferably includes a semiconductor device as described above, and one of a display device, a printing device and a computer device which is driven based on the semiconductor device. The invention thus structured provide effects similar to those described above.
In a tape carrier package type semiconductor device of a fourteenth aspect of the present invention, the semiconductor device preferably includes conductor patterns for power source and grounding, each traversing a device hole and having at least one branched connection inner lead, wherein the connection inner lead has a specified width narrower than a pad for connection to a semiconductor chip.
In accordance with the invention described above, the connection inner leads branched out from the conductor patterns are used for electrically connecting the pads provided on the semiconductor chip to the conductor patterns. As a result, the width of the conductor pattern can be made wider without making the post-connection examination difficult, and therefore the power source impedance can be substantially lowered.
As the connection inner leads are connected to a tape that forms a tape carrier, the power source conductor pattern and the grounding conductor pattern are prevented from having a slack. Therefore, these conductor patterns can be readily and correctly positioned with respect to the electrodes of the semiconductor chip. Also, the power source conductor pattern and the grounding conductor pattern may be provided with at least one or more bent sections in order to prevent growth of cracks in the conductor patterns after being assembled in an electronic device, and to thereby prevent the patterns from snapping.
An electronic device of a fifteenth aspect of the present invention preferably includes a semiconductor device as described above, and one of a display device, a printing device and a computer device which is driven based on the semiconductor device. The electronic device of the present invention thus structured provides the same effects described above.